Same happened here on the production site I manage. WP Engine initially blamed Cloudflare, but when we contacted Cloudflare Support, they were able to demonstrate that the problem was with the origin server at WP Engine via the logs. Support disabled the plugin and returned the site to operation but nothing yet on what evidence they have of the cause of the crash.
Cloudflare Support recommended using Orange-to-Orange for WP Engine so that we could control the WAF and Cache settings from our Cloudflare Enterprise account. With the current configuration with WP Engine, none of our website traffic is even visible in our Cloudflare account.
